Independent oil cavity sealing structure for a submersible electric pump

ABSTRACT

An independent oil cavity sealing structure for a submersible electric pump. The structure comprises a housing, upper and lower moving rings, upper and lower static rings, a transmission sleeve and upper and lower pressing plates; the housing is sleeved on the main shaft of the electric pump, the outer sides of the upper and lower static rings are supported on the upper and lower static ring supporting bosses through O-shaped rings respectively, the inner sides of the upper and lower static rings are tightly pressed by the O-shaped rings through the upper and lower pressing plates, the main shaft of the electric pump between the upper and lower static rings are fixedly connected with the transmission sleeve through bolts, upper and lower moving ring seats are provided in the cavity which is formed between the inner wall of the transmission sleeve and the main shaft of the electric pump.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. § 119 to Chinese PatentApplication No. 201910719314.X, which was filed on Aug. 6, 2019, theentire contents of which is hereby expressly incorporated by referencein its entirety.

TECHNICAL FIELD

The present invention relates to a sealing structure, in particular toan independent oil cavity sealing structure for a submersible electricpump.

BACKGROUND

In the design of a submersible electric pump, the submersible electricpump needs mechanical sealing parts to prevent the transmission mediumfrom entering the motor cavity. To ensure the normal use of mechanicalseals, the traditional design of an oil cavity filled with mechanicaloil uses a single or a plurality of mechanical seals for cooperation. Anoil film is formed on the friction surface of the moving and staticrings with full lubrication, ensuring the heat transfer and diffusion ofthe friction both at the same time. Because the volume of the oil cavityfor a submersible electric pump is very large, and especially in thedesign of the submersible axial mixed-flow pump, the volume of the oilcavity will be larger, and it will waste a lot of mechanical oil andhave a bloated structure, poor assembly performance, and reducedreliability.

In the prior art, a double-end mechanical sealing structure is alsoused, and the static ring at the outer end is in contact with thetransmission medium. The static ring at the end is subjected to acertain thrust force opposite to the direction of the spring force underthe action of the medium pressure. If the thrust force is longer orlarger than the reverse pressure of the spring for a long time, thestatic seal at the static ring part fails, so that the transmissionmedium enters the sealing structure. The moving and static rings at theinner end of the sealing structure are easily damaged, leading toleakage and seal failure.

SUMMARY

In view of the above problems in the prior art, at least one embodimentof the present invention provides an independent oil cavity sealingstructure for a submersible electric pump with a compact structure,convenient assembly and use, and good lubricating and sealing effect.

The technical scheme adopted by various embodiments of the presentinvention is: an independent oil cavity sealing structure for asubmersible electric pump, comprising a housing, upper and lower movingrings, upper and lower static rings, and a transmission sleeve, whereinthe independent oil cavity sealing structure further comprises upper andlower pressing plates, the housing is sleeved on the main shaft of theelectric pump, the inner walls of upper and lower parts of the housingare provided with upper and lower static ring supporting bosses facinginwards respectively, the outer sides of the upper and lower staticrings are supported on the upper and lower static ring supporting bossesthrough O-shaped rings respectively, the inner sides of the upper andlower static rings are tightly pressed by the O-shaped rings through theupper and lower pressing plates which are fixedly connected with theupper and lower inner walls of the housing, the main shaft of theelectric pump between the upper and lower static rings are fixedlyconnected with the transmission sleeve through bolts, upper and lowermoving ring seats are provided in the cavity which is formed between theinner wall of the transmission sleeve and the main shaft of the electricpump, a plurality of groups of springs provided in the axial directionof the main shaft of the electric pump abut against the part between theupper and lower moving ring seats, the upper and lower moving ringswhich are provided in the transmission sleeve are supported by theparts, opposite to each other, of the upper and lower moving ring seatsthrough the O-shaped rings, and the upper and lower moving rings abutagainst the upper and lower static rings outwards respectively.

In some embodiments, the housing comprises an upper housing cover plateand a lower housing cavity, the upper and lower static ring supportingbosses are provided on the upper housing cover plate and the lowerhousing cavity, respectively, and the upper housing cover plate istightly connected to the end cover of the support bearing of the mainshaft of the electric pump via a plurality of screws.

In some embodiments, the spring sleeved on the main shaft of theelectric pump in the axial direction of the main shaft of the electricpump abuts against the part between the upper and lower moving ringseats.

In various embodiments, the housing is filled with lubricant.

In various embodiments, the mechanical sealing structure of the presentinvention is designed as an independent structure body comprising astatic ring seat, a housing, a moving ring, a static ring and otherauxiliary parts. The bearing end cover is connected through the upperhousing cover plate. The amount of lubricant filled in the housing isonly related to the size of the mechanical seal itself, without beingrelated to the structure of the pump, which can greatly reduce theamount of mechanical seal lubricant. The heat generated by its frictionpair can be transmitted and diffused by the medium circulating aroundthe oil cavity, reducing the production cost of the pump and improvingthe product reliability.

In various embodiments, the upper and lower static rings are added withupper and lower pressing plates to be pressed in the upper housing coverplate and the lower housing cavity combined with O-shaped rings, whicheffectively avoids the problem of seal damage and failure caused by thetraditional static ring due to being subjected to the medium pressurefor a long time.

The double-end mechanical seal of certain embodiments of the presentinvention has an independent integral structure, and the performance ofthe mechanical seal is no longer limited by the technical level of theinstaller or influenced by the cumulative processing error of the waterpump parts, the quality is more reliable, the mechanism is compact, easyto assemble, and easy to form a universal modularized component, theapplication range is increased, and the cost can be saved.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of the structure according to an exampleof the present invention;

FIG. 2 is a diagram of the using state according to an example of thepresent invention.

The following reference numbers are used in the drawings: a main shaftof the electric pump 1, a lower end cover 2, a bearing end cover 3, anupper housing cover plate 4, a lower housing cavity 5, an upper staticring supporting boss 6, a lower static ring supporting boss 7, anO-shaped ring 8, an upper static ring 9, a lower static ring 10, anupper pressing plate 11, a lower pressing plate 12, a transmissionsleeve 13, an upper moving ring seat 14, a lower moving ring seat 15, aspring 16, an upper moving ring 17, and a lower moving ring 18.

DESCRIPTION OF THE EMBODIMENTS

The following is a further description of examples consistent with theinvention, with reference to the drawings and embodiments.

As shown in FIGS. 1 and 2: an independent oil cavity sealing structurefor a submersible electric pump comprises a main shaft of the electricpump 1, a lower end cover 2, a bearing end cover 3, an upper housingcover plate 4, a lower housing cavity 5, an upper static ring supportingboss 6, a lower static ring supporting boss 7, an O-shaped ring 8, anupper static ring 9, a lower static ring 10, an upper pressing plate 11,a lower pressing plate 12, a transmission sleeve 13, an upper movingring seat 14, a lower moving ring seat 15, a spring 16, an upper movingring 17, and a lower moving ring 18.

The upper housing cover plate 4 and the lower housing cavity 5 arelocked via screws through the flanges and are integrally connected bythe upper housing cover plate 4 to the lower part between the bearingend cover 3 and the lower end cover 2 of the main shaft 1 of theelectric pump. The upper housing cover plate 4 and the lower housingcavity 5 are connected across the main shaft 1 of the electric pump andits inner cavity is filled with lubricant. The upper housing cover plate4 and the lower housing cavity 5 are provided with upper and lowerstatic ring supporting bosses 6 and 7 facing inwards respectively, theouter sides of the upper and lower static rings 9 and 10 are supportedon the upper and lower static ring supporting bosses 6 and 7 throughO-shaped rings 8 respectively, the inner sides of the upper and lowerstatic rings 9 and 10 are tightly pressed by the O-shaped rings throughthe upper and lower pressing plates 11 and 12 which are fixedlyconnected with the inner walls of the upper housing cover plate 4 andthe lower housing cavity 5, the main shaft of the electric pump betweenthe upper and lower static rings 9 and 10 are fixedly connected with thetransmission sleeve 13 through bolts, upper and lower moving ring seats14 and 15 are provided in the cavity which is formed between the innerwall of the transmission sleeve 13 and the main shaft 1 of the electricpump, a plurality of groups of springs 16 provided in the axialdirection of the main shaft of the electric pump abut against the partbetween the upper and lower moving ring seats, the upper and lowermoving rings 17 and 18 which are provided in the transmission sleeve aresupported by the parts, opposite to each other, of the upper and lowermoving ring seats 14 and 15 through the O-shaped rings, and the upperand lower moving rings abut against the upper and lower static ringsoutwards respectively.

1. An independent oil cavity sealing structure for a submersibleelectric pump, comprising: a housing, upper and lower moving rings,upper and lower static rings, and a transmission sleeve, wherein theindependent oil cavity sealing structure further comprises: upper andlower pressing plates, and wherein: the housing is sleeved on the mainshaft of the electric pump, the inner walls of upper and lower parts ofthe housing are provided with upper and lower static ring supportingbosses facing inwards respectively, the outer sides of the upper andlower static rings are supported on the upper and lower static ringsupporting bosses through O-shaped rings respectively, the inner sidesof the upper and lower static rings are tightly pressed by the O-shapedrings through the upper and lower pressing plates which are fixedlyconnected with the upper and lower inner walls of the housing, the mainshaft of the electric pump between the upper and lower static rings arefixedly connected with the transmission sleeve through bolts, upper andlower moving ring seats are provided in the cavity which is formedbetween the inner wall of the transmission sleeve and the main shaft ofthe electric pump, a plurality of groups of springs provided in theaxial direction of the main shaft of the electric pump abut against thepart between the upper and lower moving ring seats, the upper and lowermoving rings which are provided in the transmission sleeve are supportedby the parts, opposite to each other, of the upper and lower moving ringseats through the O-shaped rings, and the upper and lower moving ringsabut against the upper and lower static rings outwards respectively. 2.The independent oil cavity sealing structure for a submersible electricpump according to claim 1, wherein: the housing comprises an upperhousing cover plate and a lower housing cavity, the upper and lowerstatic ring supporting bosses are provided on the upper housing coverplate and the lower housing cavity, respectively, and the upper housingcover plate is tightly connected to the end cover of the support bearingof the main shaft of the electric pump via a plurality of screws.
 3. Theindependent oil cavity sealing structure for a submersible electric pumpaccording to claim 1, wherein: the spring sleeved on the main shaft ofthe electric pump in the axial direction of the main shaft of theelectric pump abuts against the part between the upper and lower movingring seats.
 4. The independent oil cavity sealing structure for asubmersible electric pump according to claim 1, wherein the housing isfilled with lubricant.
 5. The independent oil cavity sealing structurefor a submersible electric pump according to claim 2, wherein thehousing is filled with lubricant.
 6. The independent oil cavity sealingstructure for a submersible electric pump according to claim 3, whereinthe housing is filled with lubricant.